Method of applying tar or bitumen to road surfaces



. Jan. 24,1939; Y K. ISAMMANN 2,145,158

METHOD OF APPLYING TAR'OR BIT'UMEN' TO ROAD'SURFACES Filed Sept. 1, 1936 ATTURIYEY mRL DAMMANN fnvenfor:

PatentedJan. 24, 1939 UNITED STATES METHOD OF APPLYING TAR BITUMEN 1'0 ROAD SURFACES Karl Dammann, Berlin, Germany Application September 1, 1936, Serial No. 98,973 In Germany September 4, 1935 2 Claims, (CL 9423) This invention relates to a method of applying tar or bitumen to road surfaces. I It is well known that tar or bitumen is applied to the surface of roadsto protect them against 5 atmospheric influences and the ravages of trafllc. According to the methods hitherto in use, hot tar isapplied to a road surface by means of pouring-can or sprinkling machines in a finely distributed state, or by the employment of compressed air for atomizing and finely distributing it. Both methods are, however, open to the objection that the thin film of tar immediately cools off on coming into contact with the cold surface of the road and for this reason cannot 18 thoroughly adhere thereto.

To overcome the foregoing objection is the aim of the invention and to this end the invention provides for the application to road surfaces of hot tar or bitumen from the-bottom of a trans- 20 ported body of such material disposed in superimposed relation with respect to the road surface and within a mobile carrier and simultaneously with the application of a portion of such body to the road surface, the said portion is smoothed by the carrier and which overcomes the employment of brooms or other implements for smoothing. The main advantage of the invention is that the larger amount of tar heldby the carrier prevents instant-cooling of the applied portion by theroad surface, and the heat of the applied material causes evaporation of moisture of the surface.

If the road has a relatively dense surface, such as a concrete or bitumen road, the method indicated above can be improved or rendered more effective in the following manner.

Concrete or bitumen roads mustbe very carefully built, in most cases not'so much as to impart to them the necessary strength, but to make 40 them dense enough to prevent the entrance of moisture which otherwise would destroy or impair them in winter time. In spite of greatest care this object is not always attained, and effec-.

the mobile carrier, which may be of the vacuum cleaner type and disposed in front within the carrier so as to'be surroundedby tar on all sides.

a when these suction devices are connected with a container of rarefied air, the air will be drawn out of the pores of the surface of the road and also in the immediate vicinity of the devices. Air from without cannot enter, as the suction devices are completely surrounded by tar. During travel 5 of the carrier over the surface of the road atmospheric air pressure forces the tar into the pores of the surface which are closed more effectively than was possible heretofore.

The drawing illustrates a mobile apparatus 10 capable of being used for carrying on the method in accordance with this invention, and in which: i

Fig. 1 is a side view of the apparatus, and

Fig. 2 is an enlarged perspective view of the 1 carrier and suction devices upon an enlarged scale.

With reference to the drawing l indicates a boiler for the tar or bitumen and 2 a combined receiver and carrier element for the hot material 0 which is to be applied to the road surface. The element 2 is of framelike form, open at its top andbottom, of rectangular contour and is to travel upon the road surface to which the hot material is to be applied. A supply pipe 3 ex- 25 tends from the boiler l and delivers the hot material from boiler l into the element 2 adjacent one end of the latter. The pipe 3 extends over the top edge of the said end of element 2. The boiler I is carried by a car 4 and also on the latter 30 is mounted anair vessel 5 having associated therewith a vacuum pump. A suction line 6 leads from-the vessel 5 through a tar separator 9 to a cross tube 1 arranged within the element 2. Carried by the tube I is a plurality of suction 35 heads 8 which have their intakes in contact with the road surface to be treated when the apparatus a is in use. That end of the element 2, over which the pipe 3 passe s is suitably connected to the car 4. The bottom edges of the side and end walls 40 of element 2 are provided with means, as at III to form a seal between the interior of element 2 and the portions of the road surface outwardly adjacent the side and end walls of element 2. The

means I0 is formed of any suitable material,

which is to be treated by an application of the hot material.

' I claim:

1. A method of applying hot material possessing a characteristic to adhere to a road surface, said method comprising the step of moving a confined body of the said material while the later is subjected to atmospheric pressure across, and in contact with said surface, said step providing for successive follower bottom portions of said body adhering to said surface; simultaneously with the moving'of said body across said surface, creating a continuous suction action on successive pores of said surface to evacuate the air therea from in advance of the adhering of the said successive follower bottom portions of said body to the successive evacuated pores and with the suction created means covered by said body of material for preventing the re-entry of air into the air evacuated pores; and simultaneously with the adhering of the successive follower bottom portions of said body in the evacuated pores, smoothing said portions.

2. An apparatus for applying hot surfacing material possessing an adhering characteristic to a road surface, said apparatus including a mobile combined receiving and carrying element for traveling on the road surface and for receiving a mass of the hot material, said element being in the form of a horizontally disposed rectangular frame having an open bottom and opening at the top into the atmosphere, said frame including side and end walls for confining the said mass therein, said frame being provided with sealing means throughout the bottom surfaces of its side and end walls, and a suction creating means bodily moving with said element, said means being covered by the confined mass and traveling upon the road surface at points of the latter disposed in spaced relation with respect to the ends of the frame.

KARL DAMMANN. 

